SunShield

Lifeboat Foundation SunShield

By the Lifeboat Foundation Scientific Advisory Board.
This is an ongoing program so you may submit suggestions to [email protected].

Overview

The sun’s output is quite variable, often causing the Earth to become
significantly hotter or colder. This often makes conditions on the
Earth
less than optimal.

As that enormous ball of hydrogen we call the sun gets
older, it also
gets bigger and hotter and brighter  it is
30 percent brighter now than on the day Earth was formed. By the completion of the sun’s projected
12-billion-year life cycle, it will have evaporated our oceans,
degraded our atmosphere and, in one final act, charred the Earth to its
core, eradicating it, melting it and sending every last molecule
shooting into space. This could be our long-term future unless we
decide to
do
something about it.

Near Term

Known practical methods for controlling the world’s temperature
are increasing
amount of
particulants in the air (to cool the earth) and increasing the
amount
of
greenhouse gases (to warm the
earth). Decreasing either item would have the opposite
effect. Painting a large area white or black could effect the
temperature, but this doesn’t seem practical. We are open to other
suggestions.

Even though it is known that
greenhouse gases
do increase temperature,
from about 1940 to 1970,
the Earth got
cooler despite greenhouse gases increasing. This caused many
people to
worry that we were about to enter an ice age which obviously
didn’t happen. So far no individual or organization has
a proven track record of being able to predict the world
temperature 5 or 10 years into the future. Therefore a
big goal in the short term is to be
able to understand the sun’s effects on our climate well
enough so we can make long range climate forecasts that
are good many years in advance.

Unless you know for sure
how the climate will be changing, it is unwise to spend a
lot of money trying to alter the climate, instead money should be spent
trying to understand the climate. Therefore we
support investigations into climate change such as the
Glacsweb
project led by our Scientific Advisory Board member
Kirk Martinez
which monitors glacier
behavior using sensor networks.
Let us know what ideas you have to monitor and predict climate change!

The four Inner Heliospheric Sentinels will face unique thermal and
power challenges as they orbit the Sun, some well inside Mercury’s
orbit.

Solar Sentinels

We support the idea of more “Solar Sentinels” being launched to monitor
the sun. This would include:

Inner Heliospheric Sentinels  four identical probes stationed
inside
the orbits of Venus and Mercury. These spacecraft would sample freshly
accelerated solar energetic particles close to the Sun.

Near-Earth Sentinel  single probe orbiting Earth. This Sentinel
would
carry a coronagraph, a special telescope for observing the Sun’s faint
corona where
coronal mass ejections (CMEs) get their start.

Farside Sentinel  single probe to watch the farside of the sun.
Together with other spacecraft, this sentinel would provide a complete
picture of the sun  not just the half we see from
Earth.

Artist conception of giant sun shades orbiting Earth.
Courtesy, BBC.

Future

In the future we could have orbiting
sun shades that determine how much
of the sun’s light we get.

Another idea would be to have
untethered mirrors at an altitude of 30
kilometers supported by balloons.

Long-term Solutions

Material could be mined from the sun, making it a smaller star. This
would
lengthen the sun’s life from billions of years to trillions of
years. The Earth would likely need to be moved closer to the sun if
this was done, although some compensation for the sun’s reduced output
could be achieved with additional greenhouse gases placed in our
atmosphere or more creative solutions such as covering most of the sun
with a proposed
Dyson sphere and then beaming energy captured by the Dyson
sphere to Earth.

A more extreme solution would be to turn off the Sun and deploy the
fusion fuel a lot more efficiently in controlled fusion reactors. To
take a star apart, you might use a very large gamma ray laser. Note
that the working human body has an average power density of ~3000 W/m3
but the Sun has an average power density of only ~0.3 W/m3, compared
to at least 106 W/m3 in a hypothetical fusion reactor.